Semiconductor device and manufacturing method thereof

Abstract

An object is to provide a semiconductor device having high reliability and capable of high speed operation. The semiconductor device includes a silicon substrate, a silicon nitrided oxide film formed on the silicon substrate, and a gate electrode formed on the silicon nitrided oxide film. Nitrogen is distributed only in the vicinity of an interface between the silicon substrate and the silicon nitrided oxide film. In the vicinity of the interface, every nitrogen atom is bonded to two silicon atoms and one oxygen atom.

What is claimed is:  
     
       1. A semiconductor device, comprising: 
       a silicon substrate;  
       a silicon nitrided oxide film formed on said silicon substrate; and  
       a gate electrode formed on said silicon nitrided oxide film; wherein  
       nitrogen is distributed only in a vicinity of an interface between said silicon substrate and said silicon nitrided oxide film, and  
       every nitrogen atom is bonded to two silicon atoms and one oxygen atom, in said vicinity of the interface.  
     
     
       2. The semiconductor device according to claim  1 , wherein 
       said gate electrode is a floating gate electrode,  
       said semiconductor device further comprising a control gate electrode formed on said floating gate electrode with a dielectric film interposed.  
     
     
       3. A semiconductor device, comprising: 
       a silicon substrate;  
       a silicon nitrided oxide film formed on said silicon substrate; and  
       a gate electrode formed on said silicon nitrided oxide film; wherein  
       nitrogen is distributed only in a vicinity of an interface between said silicon substrate and said silicon nitrided oxide film, and  
       nitrogen atoms each bonded to three silicon atoms exist only in said vicinity of the interface.  
     
     
       4. The semiconductor device according to claim  3 , wherein 
       said gate electrode is a floating gate electrode,  
       said semiconductor device further comprising a control gate electrode formed on said floating gate electrode with a dielectric film interposed.